Antiretroviral treatment (ART) has improved survival for people with HIV. But it cannot cure HIV as ART cannot remove HIV from cells containing virus in a resting state, known as the HIV reservoir. Current ART options usually requires daily oral medications, challenges include long-term side effects, treatment fatigue, drug resistance and expense. Broadly neutralising antibodies (bNAbs) are a new type of HIV treatment that may provide a safe, effective, and long-acting alternative to ART. Early studies suggest bNAbs may 'train' the immune system leading to long lasting HIV-specific responses. Monkeys given bNAbs early in SHIV infection, demonstrated virus control for up to 4 years. Two individuals treated with bNAbs in a small human study have unexpectedly continued to maintain undetectable virus levels in blood even beyond 30 weeks. However these studies were not randomised. The largest reservoir of HIV in the body is in the gut. It can be up to 5 times larger than in blood. It is uncertain if bNAbs enter gut tissue as well as in blood. Immune responses in the gut also differ from blood in many ways, such as slower recovery even after starting ART. Finally, we do not know how bNAbs affect the gut HIV reservoir. The RIO trial is an ongoing funded study. It compares a single dose of two types of bNAbs against inactive drug (placebo). Participants then stop ART and will return for frequent viral load tests. When the virus is detectable in blood, they will restart ART. Participants receiving placebo will be given the bNAbs after restarting ART. The RIO trial provides a unique chance to study the impact of bNAbs on the gut immune system and HIV reservoir through rectal biopsies. I will study rectal biopsies samples collected from RIO participants before and after they receive the study drugs (see Annex 1). These small 3mm biopsies are collected by an experienced clinician through a safe and painless procedure in clinic, using a short plastic tube in their rectum. This is less invasive than other common gut procedures such as colonoscopies and have minimal risks. The project aims to answer 3 research questions: 1: Are the bNAbs levels in the gut comparable to blood? Paired rectal tissue and blood bNAb levels will be measured using a highly sensitive test that can measure even single molecules of bNAbs present. If peak gut tissue bNAb concentrations are comparable to blood, these data will support further research of bNAbs for the eradication of HIV gut reservoir. This work will be done on an expected n = 10 participants who are randomised to receive the bNAbs in the main study. 2: Do bNAbs 'train' immune cells in the gut? I will use fluorescent antibody 'dyes' to look for the presence of both bNAbs and immune cells in biopsy sections through an automatic microscope. If bNAbs can 'train' HIV-specific immune responses, we will expect to see bNAbs in areas of immune cells called germinal centres. Learning how bNAbs 'train' gut immune responses may help researchers design better treatment or vaccines. 3: Do bNAbs affect the HIV reservoir in the gut? Studying resting HIV reservoir containing cells is challenging, as most contain defective HIV DNA and only about 1% contain intact HIV DNA. Cells containing intact HIV DNA are likely the source of rebound virus when ART is stopped. I will improve an existing intact HIV DNA test to sort intact from defective HIV DNA in the rectal tissue for analysis. This test will provide a more accurate, in-depth analysis of the HIV reservoir. Using the improved test, I will be able to map how the resting HIV reservoir has changed after being exposed to bNAbs. By comparing samples from the same individual, I can test if the viral reservoir has grown during ART interruption, and if bNAbs has an impact on the HIV reservoir. Findings from this project will provide insight into how the bNAbs work in the gut, and aid development of bNAbs and other strategies to eradicate the gut HIV reservoir.

Campylobacter jejuni is a bacterium that causes food poisoning. In the UK Campylobacter causes more food poisoning than other bacteria such as E. coli or Salmonella (e.g, the Food Standards Agency estimates that Campylobacter infections cost us almost one billion pounds per year). Campylobacter is also very similar to other 'dangerous' bacteria that cause other stomach problems, including cancers. If we can understand these bacteria better, we'll be better able to develop drugs to fight them. This grant proposal uses Campylobacter as an example to understand swimming in this family of dangerous bacteria. Most dangerous bacteria need to be able to swim to cause their disease, and Campylobacter swims in a very unusual manner. Most bacteria 'swim' using a miniature motor that sits in the skin of the bacterium. On the end of the motor's driveshaft is a long tail that the motor spins; the spinning long tail curls up to become a helical propeller, pushing the bacterium through its liquid habitat. Campylobacter (and family members) uses the same tail but swims in a very different way to other bacteria, and this may prove to be its Achilles heal: we may be able to develop targeted drugs that only affect Campylobacter and family. Specifically, Campylobacter uses a single very powerful motor to swim. It also uses this powerful motor to rotate its body, which is shaped like a corkscrew, allowing it to 'bore' into very thick fluids such as gut mucous easily, and therefore is better able to cause disease. But we don't understand how Campylobacter is able to do many of these things. If we can better understand the biology of this curious swimming we may be able to make drugs to prevent it. To understand bacterial swimming, it's really important to be able to see the motor and the shapes of the cell, which is a difficult task. I believe this is absolutely essential, so to visualize bacteria I trained in a technique that enables us to directly see them inside the cell, and the molecular details of the motor that drives swimming. To help me fully understand the images from this project I've recruited a stellar team of international scientists. We're still some way from using these results to fight Campylobacter food poisoning. If we had a detailed understanding of how Campylobacter swims, however, we might start designing drugs that stop it swimming. This MRC proposal requests funds to perform this research. I propose four aims: One: Campylobacter actually makes two motors, but only uses one of them (if it used both, they'd push in opposite directions!). I'll use my imaging skills to see both the active and inactive motors to understand what the difference is - in turn, telling us how it works. If we can understand how one motor is inactivated, maybe we can make drugs to inactivate both motors? Two: Campylobacter swims by rotating both its tail, and its cell body. I think I know how it divides the amount of swimming power between the two, and will test this. Three: How does Campylobacter make itself helical-shaped? I'll collect images to make progress towards understanding this. Four: Finally, I'll team up with collaborators to develop a mathematical model to combine all previous results to understand how all factors combine to produce the unique swimming of Campylobacter.

Umbilical cords are traditionally discarded after childbirth as medical waste. However, over the past few decades it has become apparent that the cord contains a small amount of immature blood cells with powerful properties to repair the human body. Cord blood is now frequently used instead of bone marrow to treat childhood blood cancers (leukaemia). Cord blood cells can also be grown to generate very large numbers of red blood cells or platelets for transfusion, or, if processed differently to create immune system cells. More recently cord blood has been proven effective, or is being clinically trialled, for a wide range of serious conditions such as organ failure, childhood brain damage or diabetes. Despite national cord blood collection and banking programmes since the early 1990's, the success of these new clinical applications will lead to unsustainable demand on already strained stocks of cord blood. In this Fellowship I intend to develop tools to help manufacture large quantities of medicinally valuable cord blood cells from the small samples retrieved at child birth. This will form the basis of a manufactured blood related bio-products industry. We will use a new technology to grow the cells in small vessels under very controlled conditions. These vessels will let us quickly and efficiently test different physical conditions (such as oxygen and acidity) and novel chemical additives on the growth of the blood cells. We will use engineering approaches to control the cells' environment in novel ways, and understand the relationships between the cells' development. We will demonstrate the conditions and systems that are necessary to grow these cells to large and clinically useful numbers. We will also understand how tolerant the manufacturing process is for repeated production of safe and effective cells. My proposed research will help the clinical community deliver a new cohort of treatments for serious diseases to patients in the UK as well as help develop an important new economic activity in the UK in the development of these new types of cell based therapies.